Re: [netmod] Management Protocol Roles: Client/Server vs Manager/Agent

Juergen Schoenwaelder <j.schoenwaelder@jacobs-university.de> Fri, 03 May 2019 16:14 UTC

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Date: Fri, 3 May 2019 18:14:50 +0200
From: Juergen Schoenwaelder <j.schoenwaelder@jacobs-university.de>
To: "Schwarz Albrecht (ETAS/ESY1)" <Albrecht.Schwarz@etas.com>
CC: Andy Bierman <andy@yumaworks.com>, NetMod WG <netmod@ietf.org>
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Subject: Re: [netmod] Management Protocol Roles: Client/Server vs Manager/Agent
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On Fri, May 03, 2019 at 10:43:50AM +0000, Schwarz Albrecht (ETAS/ESY1) wrote:

> Leading (for me) to a principle dilemma from (management) protocol engineering perspective due to
> a) Manager-to-Agent = 1:N
> b) Client-to-Server = N:1
> c) and the mapping approach in NETCONF/NETMOD of Manager-to-Client and Agent-to-Server in my understanding.

The problem is that you leave the plural 's' out. ;-)

Client-to-Server  is 1:1 (= Manager-to-Agent)
Client-to-Servers is 1:N (= Manager-to-Agents)
Clients-to-Server is N:1 (= Managers-to-Agent)

> I'm being aware that a distributed management solution needs to resolve the various role assignments in a layered management communication architecture at the various levels, e.g.,
> for Management Application MA-over-RESTCONF-over-HTTP-over-TCP-over- ... as
> 1) Application level (MA): Manager to Agent(s)
> 2) Application layer management protocol = RESTCONF: Manager to Agent(s)
> 3) Session layer = HTTP: Client(s) to Server
> 4) Transport layer = TCP: Client(s) to Server
> 
> I fail to see, or do miss the background/justification why the notion of client/server is used in RFCs about YANG, NMDA, NETCONF? Instead of manager/agent.
>

It all boils down how you define the terms Manager and Agent. With
NETCONF/RESTCONF and YANG, the initial focus was on the interaction
between the server maintaining configuration datastores and the client
manipulating configuration datastores (leaving out notifications for
now, they actually came later).

/js

-- 
Juergen Schoenwaelder           Jacobs University Bremen gGmbH
Phone: +49 421 200 3587         Campus Ring 1 | 28759 Bremen | Germany
Fax:   +49 421 200 3103         <https://www.jacobs-university.de/>